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喜马拉雅东段库曲岩体锂、铍和铌钽稀有金属矿物研究及指示意义 总被引：1，自引：0，他引：1
稀有金属矿物记录了花岗伟晶岩成岩成矿的重要信息。喜马拉雅是全球著名的淡色花岗岩带,库曲岩体位于喜马拉雅东段的特提斯喜马拉雅岩系中。本文调查了库曲岩体的二云母花岗岩、白云母花岗岩、电气石花岗岩和花岗伟晶岩,其中,花岗伟晶岩涉及花岗岩的伟晶岩相和独立伟晶岩脉。库曲岩体产出的稀有金属矿物包括锂辉石、锂绿泥石、绿柱石、铌铁矿-钽铁矿、钇铀钽烧绿石和细晶石,它们主要赋存于似文象伟晶岩、石英-钠长石-白云母伟晶岩、块体长石-钠质细晶岩、块体长石-电气石钠质细晶岩、锂辉石-块体长石-细晶岩、白云母花岗岩的伟晶岩相以及电气石花岗岩内。显微镜观察、电子探针和LA-ICP-MS测试结果显示锂辉石具有四种产状,包括粗粒锂辉石自形-半自形晶、细粒锂辉石-石英镶嵌晶、中细粒锂辉石-钾长石-钠长石-云母镶嵌晶以及发育锂绿泥石的粗粒锂辉石,揭示了其形成时复杂的熔流体动荡结晶环境。绿柱石背散射电子图像（BSE）下呈均一结构和不均一结构（蚀变边、不规则分带和补丁分带）,元素替代机制包括通道-八面体替代、通道-四面体替代以及通道中碱金属阳离子间的置换。铌铁矿族矿物包括原生、蚀变边和不规则分带结构,部分被钇铀钽烧绿石和细晶石交代。与原生铌铁矿相比,蚀变边和不规则分带铌铁矿族矿物总体上富钽贫锰,显示了结晶分异、过冷却引起的过饱和以及流体作用。根据稀有金属矿物揭示的成因信息,独立伟晶岩脉（似文象伟晶岩）、白云母花岗岩的伟晶岩相和电气石花岗岩在岩浆分异程度、经历的演化过程、以及流体活动方面存在差异,很可能是不同期次岩浆活动的产物。库曲岩体绿柱石的Rb和Zn含量、以及铌铁矿族矿物的Sc2O3、SiO2和PbO含量,与已有指示标志存在相关性,作为潜在指示标志仍需开展更多的研究工作。综合含锂辉石伟晶岩的产出、岩浆分异演化程度、多期花岗质岩浆活动、复杂的流体作用以及所属锂丰度高值区等因素,库曲岩体是喜马拉雅东段找锂的有利地段。 相似文献
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长江岩体是诸广南部地区重要的产铀花岗岩体之一,此次研究运用电子探针和扫描电镜对长江岩体新鲜花岗岩和
蚀变花岗岩中的绿泥石和有关含铀矿物进行了精细对比,揭示花岗岩中铀的活化与成矿前期或早期致使花岗岩发生绿泥
石化的还原性热液蚀变作用关系密切,黑云母等的绿泥石化蚀变,使其中包裹的一些含铀副矿物也发生蚀变,导致原来
以类质同象形式存在于副矿物中的惰性铀转变成活性铀,并在绿泥石附近沉淀成铀石等铀含量高且在成矿期低度氧化性
热液作用下容易释放铀的矿物。长江岩体中的副矿物有锆石、磷灰石、褐帘石、铀石-钍石、晶质铀矿、独居石等,其
中,晶质铀矿、铀石、铀钍石中铀含量高且铀容易释放,是长江岩体的主要铀源矿物;独居石中铀含量较高,当其周围
矿物绿泥石化时,独居石蚀变形成直氟碳钙铈矿并释放铀,因而也是长江岩体的潜在铀源矿物;锆石中铀含量虽高,但
因其结构稳定,铀难以释放,因此它不是长江岩体中重要的铀源矿物;磷灰石、褐帘石中铀含量均低于检测限,作为铀
源矿物的可能性很小。 相似文献
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570矿床主要矿石矿物的成分特征 总被引：1，自引：0，他引：1
本文对５７０矿床的主要矿石矿物（沥青铀矿、铀石、钛铀矿及胶硫钼矿）的化学组成进行了研究。沥青铀矿的铀含量较高（ＵＯ２＋ＵＯ３）＝８４．４％￣９１％，并含有一定量的Ｃａ、Ｓｉ、Ｐ和Ｔｉ等，而Ｔｈ和ＲＥＥ的含量低，表明沥青铀矿的低温成因。在电镜下观察到钛铀矿与钛的氧化（金红石或锐钛矿）成交代关系，说明钛铀矿是交代成因的。胶硫钼矿中的银含量很高（０．５％￣１．６％），是该矿床伴生银的富集矿物及携带矿物， 相似文献
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从热力学角度探讨构造热液中铀的溶存形式,迁移及沉淀机理 总被引：2，自引：0，他引：2
本文从热力学计算入手，以２００℃的Ｕ－Ｃ－Ｏ－Ｈ体系为例，从Ｅｈ，ｐＨ，Ｔ，Ｐｃｏ＿２及∑Ｕ五方面探讨构造热液中铀的溶存形式及其迁移、沉淀机理。结果表明：Ｅｈ，ｐＨ降低不仅改变铀的溶存、迁移形式，而且使其还原成低价态沉淀析出；Ｔ升高会降低构造热液的Ｅｈ，ｐＨ值，使ＵＯ＿（２（ｓ））稳定区间增大，从而控制了溶存、迁移形式的优势分布；Ｐｃｏ＿２降低会使构造热液产生沸腾，逸出ＣＯ＿２，有利于铀的还原析出，而铀矿床的形成离不开丰富的活性铀源，这是维持构造热液具一定浓度的铀，从而使矿化顺利进行的不可缺少的前提。 相似文献
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烧绿石超族矿物是指通式为A2-mB2X6-wY1-n(m=0~1.7,w=0~0.7,n=0~1.0)的氧化物。IMA-CNMNC2010年批准了烧绿石超族矿物分类命名的新方案,该方案中将B类离子用于分类,而A、Y类离子用于命名,并对已发表的烧绿石类矿物进行了重新认定。目前已有16个烧绿石超族矿物种被IMA-CNMNC正式认可,另有15种被定义为可能的新矿物种,但尚待进一步研究,在充分描述后有望得到IMA的批准承认,所有不符合新命名规则的矿物名称都将废弃。我国的烧绿石超族矿物较为丰富,并有其特点,同一个矿区产出的不同颗粒其主要成分含量变化较大,部分含放射性元素的矿物有不同程度的非晶质化。对其进行的化学成分分析、X射线衍射分析及晶体结构和离子占位研究对该类矿物的分类命名有重要意义。 相似文献
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5—Br—PADAP分光光度法测定多金属结核中的铌 总被引：4，自引：1，他引：4
报道了用单宁＿硅酸钠＿动物胶沉淀分离多金属结核中的Ｍｎ、Ｃｏ、Ｆｅ、Ｓｉ等干扰组分，然后用５＿Ｂｒ＿ＰＡＤＡＰ分光光度法在水相中测定Ｎｂ；讨论和解决了Ｎｂ的结果偏低问题。方法应用于新研制的大洋多金属结核ＧＳＰＮ＿２和ＧＳＰＮ＿３中Ｎｂ的定值测定，结果与初定值相符，其ＲＳＤ（ｎ＝７）分别为２０１％和３２２％。 相似文献
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A systematic and rational nomenclature of minerals of the pyrochlore group are developed based on the results obtained by processing 671 chemical analyses of pyrochlore-group minerals from carbonatite complexes, alkali rocks, and their pegmatites, granite pegmatites, and alkali and albitized granites. The proportions of Nb, Ta, and Ti are typomorphic of pyrochlore from these four types of geological environments. The paper lists pervasive characteristics of the distribution of Na and Ca, REE, Th and U, Sr and Ba, K and Cs, Pb, Sn, Sb, and Bi in the minerals. Based on the occurrence of compositions with elevated concentrations of typomorphic elements at site B in the structure of the minerals, pyrochlore subspecies are recognized: pyrochlore, Ta-pyrochlore, Ta,Ti-pyrochlore, Zr-pyrochlore, Nb-betafite, Ta-betafite, Ti-betafite, Ti-microlite, Nb,Ti-microlite, Nb-microlite, and microlite, as well as 60 geochemically significant varieties with the predominance of certain cations at site A (REE-pyrochlore, U-pyrochlore, etc.). Aspects of a rational systematics of minerals of complicated isomorphic series are discussed. 相似文献
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《矿物学报》2013,(Z1)
The pyrochlore supergroup natural minerals are the oxides for formula A2-xB2O7. In this formula, A typically is Ca, Na, TR, Ba, Fe and Mn cation. B is Ta, Ti, Nb, W, Sb. The pyrochlore supergroup is divided into five groups basis of the atomic proportions of the B-site atoms Nb, Ta, Sb, Ti, and W. They are pyrochlore, microlite, roméite, betafite, and elsmoreite, respectively. Some of these minerals containing rare-earth elements species or synthetic oxides have important applications in materials, as for optical materials, light catalyst materials, magnetoelectric materials and radioactive waste treatment etc. 相似文献
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Savelyeva V. B. Bazarova E. P. Khromova E. A. Kanakin S. V. 《Geology of Ore Deposits》2018,60(8):643-657
The chemical composition and origin of major REE minerals of aegirine, aegirine–arfvedsonite, arfvedsonite, and annite–riebeckite–arfvedsonite granites are studied for the Katugin Ta–Nb–Zr–Y deposit with cryolite in the southwestern part of the Aldan Shield. The REE mineralization of granites includes two types: (i) disseminated grains of pyrochlore and, to a lesser extent, other Nb–Ln oxides, Ln phosphates, and Ln–F carbonates in association with zircon, ilmenite, sphalerite, and other minerals and (ii) interstitial intergrowths of Ln fluorides.
相似文献14.
Two mineralogically different rare metal granites located in two distinct terranes from the Tuareg area are compared: the Tin-Amzi granite in the north of the Laouni Terrane and the Ebelekan granite in the Assodé–Issalane Terrane.The Tin-Amzi granite is enclosed within Eburnean granulitic gneisses, and consists of albite, quartz, protolithionite, K-feldspar and topaz granite (PG). The accessory minerals include columbite tantalite, U- and Hf-rich zircon, Th-uraninite, wolframoixiolite and wolframite. This facies is characterised by a mineralogical evolution from the bottom to the top underlined by a strong resorption of K-feldspar and albite and the crystalliK-feldspar of more abundant topaz and protolithionite II which is further altered in muscovite and Mn-siderite. It is underlain by an albite, K-feldspar, F-rich topaz, quartz and muscovite granite (MG), with W–Nb–Ta oxides, wolframite, Nb-rutile, zircon and scarce uranothorite as accessories.The Ebelekan granite intrudes into a coarse-grained biotite granite enclosed within upper amphibolite-facies metasediments. It comprises a zinnwaldite, albite, topaz porphyritic granite (ZG) with “snow ball” quartz and K-feldspar. The accessories are zircon, monazite, uranothorite, Ta bearing cassiterite, columbite tantalite and wodginite. It is capped by a banded aplite-pegmatite (AP).The geochemistry of Tin-Amzi and Ebelekan granites is nearly comparable. Both are peraluminous (A/CNK=1.10–1.29; ASI=1.17–1.31), sodolithic and fluorine rich with high SiO2, Al2O3, Na2O+K2O, Rb, Ga, Li, Ta, Nb, Sn and low FeO, MgO, TiO2, Ba, Sr, Y, Zr and REE contents. These rare metal Ta bearing granites belong to the P-poor subclass, relating to their P2O5 content ( 0.03–0.15 wt.%). Nevertheless, they are distinguished by their concentration of W, Sn and Ta. The Tin-Amzi granite is W–Ta bearing with high W/Sn ratio whereas the Ebelekan granite is Ta–Sn bearing with insignificant W content.At Tin-Amzi the W–Nb–Ta minerals define a sequence formed by W-columbite tantalite followed by wolframoixiolite and finally wolframite showing the effect of hydrothermal overprinting with an extreme W enrichment of the fluids. At Ebelekan, the Sn–Nb–Ta oxides follow a Mn sequence: manganocolumbite→manganotantalite→wodginite+titanowodginite→cassiterite that represents a trend of primary crystallisation resulting from progressive substitution Fe→Mn and Nb→Ta during the magmatic fractionation. 相似文献
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《International Geology Review》2012,54(1):9-25
Ta and Nb are associated in nature. Both are oxyphile and are related geochemically to Fe, Mn, Ti, rare earths U, Th, Zr, W, Sn, Bi, and Sb. Both accompany the alkali metals,especially Na and Li. Their close relationship explains their isomorphism in mineral-forming processes. Zr, W, and Sn entrain Ta and Nb in the crystal lattices of their minerals in limited amounts. The concentration of Ta and Nb increases in the course of magma evolution from ultrabasic to alkalic. Nb predominates over Ta in the main kinds of rocks by from 5:1 to 17:1. Only in granite pegmatites is Ta dominant. In granitic rocks Ta and Nb are associated with Fe, Mn, Bi, Sb, W, and Sn. In granosyenitic complexes they form complex minerals with Ti, rare earths of the Y subgroup, U, and Th. Concentrations of Ta and Nb in granitic and granosyenitic complexes increase toward the end of the magmatic and pegmatitic processes, and afterward diminish toward the end of the pneumatolytic-hydrothermal processes. In alkalic complexes Ta and Nb are associated with Ti, rare earths of the Ce group, and Th. Concentrations of Ta and Ni in alkalic massifs are caused by magmatic differentiation. In alkalic ultrabasic complexes, in magmatic and pegmatitic processes, Ta and Nb do not form independent minerals but enter into minerals of Ti and Fe, i. e. perovskite, titanomagnitite, and pyroxenes. --M. Russell. 相似文献
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苏州善安浜超大型钽矿地质特征及找矿前景 总被引：1，自引：1，他引：0
善安浜地区钽矿找矿的突破,是江苏省地质调查研究院近几年开展国土资源大调查所取得的重大成果.该矿床为碱性长石花岗岩型钽矿床.矿体赋存在隐伏花岗岩体隆起部位的顶部,自上而下分为三个矿体,呈上钽下铌关系产出.矿石类型主要为钠长石花岗岩型,次为少量花岗伟晶岩型.矿石主要有益组分为钽、铌,伴生有益组分为锂、铷、铯、锆、铪.钽、铌主要赋存在铌铁矿-钽铁矿中,铌铁矿-钽铁矿主要嵌布在长石、石英等矿物颗粒间,矿石可选性好.估算的资源量:钽达超大型矿床规模,铌达中型矿床规模.该矿床的发现不仅对苏州西部稀有金属矿地质找矿有重要指导意义,亦为平原区隐伏矿床的找矿研究提供了典型实例. 相似文献
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我国稀土铌钽矿物学研究回顾与展望 总被引：3，自引：0，他引：3
作为高新技术原料用的稀土铌钽是国家发展的支柱之一, 稀土铌钽矿物学研究在与国家的技术进步同步前进。 通过研究,已经获得了我国产出的全部百余种稀土铌钽矿物的化学组成、物理性质、稀土配 分、结晶参数、共生组合和产状成因的全面系统的鉴定描述成果;发现了多种稀土铌钽新物,并提出许多新规律和新理论,建立了易解石和褐钇铌矿两个新的矿物族;确定了稀土铌钽铁锰钨的复杂氧化物的晶体结构关系;确立变生矿物学为矿物学研究的一个特殊分支,探讨了稀土次生富集的离子型稀土矿成矿机理。 相似文献
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S. G. Viladkar U. Bismayer P. Zietlow 《Journal of the Geological Society of India》2017,89(2):133-138
U-rich pyrochlore (UO2 up to 18.63%) occurs along the magmatic bands as well as disseminated grains within rauhaugites of the Newania complex. UO2 appears to be primary as it seems mostly evenly distributed all over the grains, though in one grain it does show concentration in parts. Ta is also an important element in some pyrochlore grains and its concentration reaches up to 17.15%. High U and Th are responsible for bringing metamictization in the Newania pyrochlore. Newania carbonatite has a complex emplacement history; rauhaugite seems to have been replaced at 2200 Ma years followed by emplacement of ankeritic carbonatite at around 1500 Ma. Later during tectonic event pyrochlore was involved in reaction with hydrothermal fluid and at this stage Fe and FeS were deposited on the rims of pyrochlore grains. At the same time pyrochlore was subjected to hydrothermal alteration resulting in removal of Na, Ca and F leaving large vacancy in its A-site. Very few grains have escaped such alteration. 相似文献
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吉林省集安县上绿水桥岩体主要岩石类型为晶洞碱长花岗岩。岩石的化学成分具有高硅（SiO2质量分数为75.94%~76.34%）、富碱（ALK质量分数为8.29%~9.63%）、高TFeO/MgO值（比值为39.6~66.1）、富钾（K2O质量分数为5.14%~5.20%,K2O/Na2O值为1.47~1.68）、低CaO和TiO2的特点;强烈亏损Ba、Sr、Ti、Nb、Ta、P,富集K、Rb、Th等亲石元素;具有右倾海鸥型的球粒陨石标准化稀土配分型式及强烈的负铕异常等。主量和微量元素研究表明,上绿水桥岩体为铝质A型花岗岩（A/CNK为0.99~1.10,A/NK为1.05~1.16）。LA-ICP-MS锆石U-Pb定年结果为（117.8±2.3）Ma,属早白垩世侵入体。岩体具有相对较低的Ce/Nb、Y/Nb、Yb/Ta值,为A1型非造山花岗岩,是华北板块东部岩石圈减薄在吉南地区的浅部地质响应。 相似文献
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江西雅山黄玉锂云母花岗岩属典型的华南[富氟高磷花岗岩（P2O5＝0．15％－0．55％），表现为富氟（F＝1．07％－2．04％），强过铝性（A／NKC＝1．26－1．60），具有很高的Li,Rb,Cs,Be,Nb,Ta含量和很低的Y、REE含量.磷锂铝石是雅山黄玉锂云母花岗岩中的主要磷酸盐矿物，其产出与否同体的Li,Rb,Cs含量密切相关；磷锂铝石和长石矿物都是雅山黄玉锂云母花岗岩中磷的主要贮体，并且相互之间呈互补关系，当出现磷锂铝石时，磷锂铝石为全岩磷的主要贡献者，当无磷锂铝石晶出时，长石矿物为全岩磷的主要贡献者，体系的强过铝性以及很低的REE，Y，Ca含量使得磷灰石，独居石，磷钇矿都难以达到饱和结晶，磷灰石为少量出现，并且大部分为晚期形成；独居石和磷钇矿都为极少出现，反映出雅山岩体演化过程中具有独居石，磷钇矿等稀土磷酸盐矿物的结晶分离，铍磷酸盐矿物－羟磷铍钙石的出现反映了雅山黄玉锂云母花岗岩存在岩浆期后的含Be,Ca热液流体的作用。 相似文献